The field of the disclosure relates generally to management of wireless communication systems, and more particularly, to placement of wireless small cell communication systems.
Conventional communication systems include wired networks (e.g., cable, fiber optic, hybrid fiber coaxial (HFC), etc.) and wireless technologies (e.g., Wi-Fi, Bluetooth, Zigbee, Long Term Evolution (LTE), etc.). Some HFC networks include Wi-Fi and/or small cell LTE within the communication system of the network. However, transmissions from a mobile macrocell or a macro base station (Macro BS) within the operational vicinity of the HFC network may interfere with the cable television (CATV) signals throughout the network. An illustrative example of such interference is shown below with respect to FIG. 1.
FIG. 1 illustrates a conventional LTE channel plan 100. As illustrated in FIG. 1, LTE channel plan 100 includes an LTE band plan 102, and is superimposed on a CATV sub-band 104. In this example, LTE band plan 102 is shown to include the 700 MHz range, and CATV sub-band 104 is shown to include channel 108 (696-702 MHz) through channel 126 (804-810 MHz). From the example illustrated in FIG. 1, it can be seen how interference occurs when the 700 MHz LTE frequencies ingress the cable plant on CATV channels. Since the 700 MHz modulation is digital, the interference will appear as an increase in the noise floor in the CATV program or data channel. That is, LTE in the 700 MHz range is a major source of interference for the cable signal. This interference may drive error rates beyond a tolerable level, and further cause the collapse of digital programming. In one instance, a multiple-system operator (MSO) was forced to abandon cable channels 116 and 117 due to interference 106 from a wireless LTE mobile network operator (MNO) downlink.
FIG. 2 is a schematic illustration depicting a conventional cable network 200 operating within the vicinity of a macro base station 202. In this example, macro base station 202 represents a transmitting portion of a wireless LTE MNO, and network 200 is an HFC network operable to provide video, voice, and data services to subscribers. Network 200 includes a master headend/hub 204, a node 206, and at least one long fiber or cable 208 (e.g., up to 80 km) connecting headend/hub 204 with node 206. In some examples, headend/hub 204 includes a plurality of headends and/or hubs connected over an optical link (not shown). In this example, headend/hub 204 is in operable communication with at least one satellite earth station/dish 210, the Internet 212, and the public switched telephone network (PSTN) 214. Node 206 connects with a plurality of trunk cables 216 (three shown in this example) that each service a respective service area 218. Each service area 218 may service between 125 and 500 end users 220 (e.g., homes/residences or businesses) that each include at least one cable modem (CM) (not separately shown) connected to a respective trunk cable 216 by one or more drop cables 222.
In operation of network 200, macro base station 202 transmits an LTE signal 224 within the vicinity of a portion 226 of trunk cable 216(1), and thereby introduces interference into the cable signal carried along trunk cable 216(1) that affects all CMs 220 from the point of interference or leakage (i.e., portion 226) onwards (e.g., service area 218(1)). This LTE interference poses an additional problem with respect to inclusion of a small cell base station 228 within the service area 218(1) as another type of end user. Small cell base station 228 is considered “small” with respect to macro base station 202 because small cell base station 228 generally includes a low-powered cellular radio access node having a range of 10 meters to a few kilometers, which is a considerably shorter range than that of macro base station 202, and will also typically handle fewer concurrent calls or sessions. Conventional techniques rendered difficult to determine whether placement of small cell base station 228 at the desired location is operationally safe. Furthermore, conventional techniques do not easily detect if LTE interference is present in the given cable plant, nor do they enable the station operator to estimate a safe distance of small cell base station 228 from ingress-affected CMs 220.
Conventional small cell placement techniques utilize a drive test to assess interference and determine optimum small cell placement. Requiring the drive test for the placement of every small cell base station, however, is a significantly expensive assessment cost, and requires considerable human and equipment resources. Accordingly, it is desirable to be able to determine optimum small cell placement using existing technology already in use in the field.